Lipid Rescue

This short case report from Emory University and the Georgia Poison Center makes the point that administering lipid rescue therapy (LRT) may affect laboratory results in ways that may be unanticipated. In the case, a 54-year-old man who ingested a mixed overdose of diphenhydramine, amitriptyline and acetaminophen. His initial aspartate aminotransferase level (measured on a Siemens Vista 1500 analyzer) was 138 U/L. After 20% IV lipids were given, a repeat AST level was undetectable. Eight hours later serum AST was 488 I/U; the peak AST was 1600 U/L. The authors note that large lipid droplets interfere with some colorimetric analysis. Not all of these interference patterns are necessarily listed by the manufacturer. Their conclusion:

We advise that clinicians repeat suspected abnormal laboratory values before acting upon them and, when erroneous laboratory values are suspected, obtain the limits for interferent levels of the assay by contacting laboratory or pathology personnel. Be aware of the potential of extreme lipemia, particularly after intravenous LRT therapy, to alter assays that use spectrophotometric analysis. Techniques such as dilution and centrifugation can be used with varying success in removing the lipemic interference

– See more at: http://www.thepoisonreview.com/2013/08/21/lipid-rescue-therapy-can-cause-lab-errors/#sthash.ge1axiNb.dpuf